Kabul: US Defence Secretary Robert Gates said yesterday the United States has no evidence Iran's government is behind a flow of weapons from Iran to Taliban insurgents in Afghanistan.

On his second visit to Afghanistan since taking over the Pentagon in December, Gates met Afghan President Hamid Karzai, who also said there was no evidence Iran was supplying the Taliban.

"There have been indications over the past few months [that] weapons are coming in from Iran," Gates told a news conference with Karzai at the national palace.

"We do not have any information about whether the government of Iran is supporting this, is behind it, or whether it is smuggling, or exactly what is behind it."

Coordination

"But there clearly is evidence that some weapons are coming into Afghanistan destined for the Taliban, but perhaps also for criminal elements involved in the drug trafficking coming from Iran," he said.

US officials accuse Iran of meddling. The top US general, Joint Chiefs of Staff Chairman Peter Pace, said on Sunday that Iranian-made weapons had been found inside Afghanistan.

Gates's one-day visit is aimed at assessing coordination within the US-led coalition to ensure Afghanistan does not spiral into the kind of violence seen in Iraq.

Afghanistan is the world's largest producer of opium and supplies about 90 per cent of the world's heroin. Authorities say heroin profits help fund the Taliban, waging an insurgency since they were ousted from power by a US-led invasion in 2001.